Cal. Pub. Resources Code § 753
"Forestry," as used in this article, refers to the science and practice of managing forested landscapes and the treatment of the forest cover in general, and includes, among other things, the application of scientific knowledge and forestry principles in the fields of fuels management and forest protection, timber growing and utilization, forest inventories, forest economics, forest valuation and finance, and the evaluation and mitigation of impacts from forestry activities on watershed and scenic values, to achieve the purposes of this article. The practice of forestry applies only to those activities undertaken on forested landscapes. The professions specified in Section 772 are not practicing forestry when mitigating or recommending mitigation of impacts from previous forestry activities on related watershed or ecological values within their area of professional expertise or when recommending those mitigations for proposed timber operations. However, public and private foresters are required to be licensed pursuant to this article when making evaluations and determinations of the appropriate overall combination of mitigations of impacts from forestry activities necessary to protect all forest resources.
Ca. Pub. Res. Code § 753